Currently, data sharing between client-ends may be implemented by establishing a connection channel between the client-ends, and performing data transmission between the client-ends by using the connection channel. Data transmission between client-ends may be implemented by using a universal serial bus (USB) data line. For example, an intelligent mobile terminal establishes a connection channel by connecting a USB data line to an in-vehicle infotainment system, and data of a client-end in the intelligent mobile terminal is transmitted to a client-end of the in-vehicle infotainment system by using the USB data line. After the intelligent mobile terminal downloads a complete to-be-played file (for example, a to-be-played file of an audio type) from a network, the client-end of the intelligent mobile terminal transmits transmission data of the to-be-played file to the client-end of the in-vehicle infotainment system by using the USB data line. The client-end of the in-vehicle infotainment system receives the transmission data of the to-be-played file, and plays the audio type file according to the transmission data of the to-be-played file. According to this method, a formal connection needs to be established. Data can be transmitted between terminals corresponding to client-ends only when the connection is successful. Therefore, a transmission process is long. When the USB data line is damaged, or the length of the USB data length is insufficient, the terminals corresponding to the client-ends cannot be connected. Consequently, data transmission between the client-ends cannot be performed.
Alternatively, the data transmission between the client-ends may be implemented by using a Bluetooth connection. For example, before data is transmitted between a client-end of a mobile communications terminal and a client-end of an in-vehicle infotainment system, the mobile communications terminal and the in-vehicle infotainment system need to enable a Bluetooth function. Only when the mobile communications terminal and the in-vehicle infotainment system satisfy the standard of the Bluetooth Special Interest Group, a connection channel between the client-end of the mobile communications terminal and the client-end of the in-vehicle infotainment system can be established. A to-be-played file of the mobile communications terminal is transmitted to the in-vehicle infotainment system by using a Bluetooth transmission protocol for play. The Bluetooth is a wireless technology standard. By means of the Bluetooth, only data exchange within a short distance can be implemented, and a transmission process is relatively long. Only when client-ends satisfy the standard of the Bluetooth Special Interest Group, a connection can be established. When client-ends do not satisfy the standard of the Bluetooth Special Interest Group, or a distance between client-ends is relatively long, it is difficult to implement data transmission between the client-ends.